typhoid vaccine, live oral

Vivotif is a live attenuated bacterial vaccine containing the attenuated Salmonella typhi strain Ty21a, which is derived from the wild-type strain S. Typhi Ty2. It is indicated for active immunization against typhoid fever caused by S. typhi in adults and children over six years of age. The vaccine works by introducing weakened bacteria into the digestive system, which stimulates both local gut-associated lymphoid tissue immunity and systemic immune protection. It is administered orally as enteric-coated capsules, typically in a four-dose regimen on alternate days. Originally commercialized by PaxVax, the vaccine was acquired by Emergent BioSolutions in 2018 and subsequently sold to Bavarian Nordic in 2023. It is primarily used for travelers to endemic regions, individuals with intimate exposure to S. typhi carriers, and laboratory personnel working with the bacterium.

Brand names

Vivotif

Other names

Salmonella typhi strain Ty21aTy21aTy-21aTy 21aoral typhoid vaccine